title: A rapid paper-disc test for penicillinase.
abstract: A practical acidimetric assay for penicillinase production using penicillin and phenol red impregnated in paper discs was developed. Blank discs were first impregnated with buffered penicillin G and, after drying, with 1% phenol red. For use, a disc was added to a bacterial suspension made in saline solution. A yellow color within 1 to 30 min of incubation indicated penicillinase production. These discs were tested against Staphylococcus aureus, Haemophilus influenzae, and Neisseria gonorrhoeae, and the assay was found to be a simple, rapid, and accurate method for detection of penicillinase.
mesh_terms: D001419:Bacteria / Q000187:drug effects / Q000201:enzymology*; D001431:Bacteriological Techniques / Q000295:instrumentation; D006193:Haemophilus influenzae / Q000201:enzymology; D008826:Microbial Sensitivity Tests; D009344:Neisseria gonorrhoeae / Q000201:enzymology; D010400:Penicillin G / Q000494:pharmacology; D010405:Penicillinase / Q000378:metabolism*; D013211:Staphylococcus aureus / Q000201:enzymology; D001618:beta-Lactamases / Q000378:metabolism*
chemical_list: D010405:Penicillinase; D001618:beta-Lactamases; D010400:Penicillin G